Corrosion inhibitor



Patented June 25, 1940 .UNlTE STAT CORROSION INHIBITOR William J. Sweeney, Westfield, and Emile L. Baldeschwieler, Grantord, N. J., assignors to Standard Oil Development Company, a corporation of Delaware No Drawing. Application March 4, 1939, Serial No. 259,902

7 Claims.

This invention relates to compositions for protecting metals of various kinds from corrosion, especially metals that are used in the construction of containers for various fluids.

Airports provided with wide level flying fields over which the planes taxi when taking oil and when landing must be provided with fueling stations. The ordinary upstanding meter casings almost universally used in automobile fueling stations for dispensing gasoline are objectionable on such fields because of the danger of their being struck by taxiing planes. Fueling outlets that are suitable are those that may be submerged so that when not in use they are covered, leaving a clear open flying field. As all the working parts oi fueling stations are at times covered over, being below the level of the flying fields, the use of pumps is avoided for obvious reasons, such as water flooding, etc. Therefore, the containers used for gasoline are generally connected with city mains whereby the pressure of the city mains is used to force the gasoline from the containers to the various tanks of the planes. The containers are also connected to the sewer so that when being filled with the water may flow out through the sewer outlet. One of the difficulties encountered using water in a system of this particular type is the corrosion that results. The tanks are composed of metals, such as iron,

39 aluminum, brass, Zinc, etc, and generally tend to corrode. The ordinary corrosion. inhibitors used to prevent corrosion are water soluble and. necessarily need. continuously as more water is added, as the first part is lost for fur- 35 ther use as the water is allowed to flow to the sewer. The gasoline stored in this manner, when run into tanks to be used to run motors, may carry some water over mechanically or dissolved therein, after which it is precipitated by a drop it in temperature and it is desirable that this watcr also be treated so that no corrosion will take place in the tanks. In the handling of other fluids, such as heavier oils or greases, corrosion also results when water is present, especially the soap, which on hydrolysis forms corrosive compounds.

A further object of this invention is to provide an inhibitor which is substantially inert and not readily soluble that will prevent corrosion of 5 containers used for storage of various compositions which tend to corrode the containers.

According to this invention, it has been found that the yellow, very slightly water-solublealkali salts of uranium will inhibit corrosion of metals, particularly the corrosion of aluminum. Aluminum, when submerged in water containing 2% of sodium chloride, after 96 hours shows a loss in weight of 0.9 milligram per gram. On the other hand, if the water has .02% of yellow sodium uranate in solution, after 96 hours there is no loss in weight of the aluminum when submerged in water containing 2% of sodium chloride. Both the yellow sodium and'ammonium uranates were found to be effective and as they are slightly soluble in water, they may be' introduced into the container and confined in a narrow space by means of a fabric, such as a porous cloth bag. The water circulating throughthe container will only remove a very slight amount of the uranates 25 at each throughput, that is, as the tank is filled with" water and emptied, there is only a very little loss of the corrosion inhibitor. In grasses and oils where the presence of the yellow sodium or ammonium uranate is not objectionable, they may be added in proportions of about .02% to I prevent corrosion of the metal that may be caused by separation of the water. In liquids or oils where there may be some accumulation of water that had been mechanically carried over or precipitated out by the change in temperature, a small bag or fabric container filled with sodium and ammonium uranates retained at the lowest part of the container will inhibit corrosion.

Efiect of yellow alkali uranates on aluminum corw rosz'on. Aluminum metal sheet half immersed in distilled water covered with gasoline Hours of standing before corrosion Inhibitor We claim: 1. A method of inhibiting corrosion in a metal container containing a motor fuel which 'comprises suspending in the lower part oi the metal container a porous cloth bag containing yellow, very slightly water-soluble alkali urenates.

2. A method of inhibiting corrosion in a. metal container containing a motor fuel which comprises suspending in the lower part oithe metal container a porous cloth bag containing yellow sodium uranate.

3. A method of inhibiting corrosion in a metal container containing a motor fuel which coniprises suspending in the lower part of the metal container a porous cloth bag containing yellow ammonium uranate.

e. A process for preventing deterioration of naphtha comprising maintaining the product in liquid condition in direct contact with a yellow,

very slightly water-soluble mono-valent salt of a.

yellow uranate- 5. A method of inhibiting corrosion in a metal 1 aeoareecontainer containing a motor fuel which comprises maintaining in the lower part or the metal container a porous holder containing yellow, very slightly water-soluble alkali uranates.

6. A method of inhibiting corrosion in a metal container containing a. motor fuel which comprises suspending in the lower part of the metal container a. yellow, very slightly water-soluble alkali uranate' by means 01' a holder through which the motor fuel and the uranate remain in contact and the uranate is retained at one definite point of the holder until used up,

7. The method of protecting the inner surface of 'ametal container against the corrosive eflects of a lubricant comprising incorporating in said lubricant at least about .02%. of a. yellow, very slightly water-soluble alkali salt of uranium.

' WILLIAM J. SWEENEY.

EMILE L. BAIDESCHWEIER. 

